Diethyl Oxalate → HCID 20305122, compound

Participants

Reaction Conditions

Reaction Steps

A solution of 96 g (0.44 mol) of 4-[2-(3-carbomethoxypropyl)phenyl]-2-butanone, 10, and 129 g (0.88 mol) of diethyl oxalate was added dropwise at room temperature to a solution made by dissolving 20.2 g (0.88 g-atm) sodium in 200 ml absolute ethanol. After the addition was complete, the reaction was stirred 1 hour at room temperature and 1 hour at 50° C. It was then concentrated, the residue taken up in H2O, and acidified with 70 ml concentrated HCl. The precipitated material was extracted into ether and washed twice with H2O. The acidic material was then extracted out of this ether phase with aqueous sodium carbonate solution. Upon acidification of the sodium carbonate solution a red oil separated. This oil was heated overnight in a solution of 200 ml concentrated HCl and 200 ml methanol. The reaction mixture was diluted with 300 ml H2O and extracted with ether. Evaporation of the ether gave 70 g of red oil. This was chromatographed on 400 g silicic acid and eluted with benzene:ethanol. Like fractions were combined and crystallized. Recrystallization from benzene gave 23 g of the trione acid 11, mp 123° C.

Provenance & Evidence